Affiliation: | (1) Texas Transportation Institute, 3135 TAMU, College Station, TX 77843-3135, USA;(2) National Research Center for Statistics and the Environment, University of Washington, Seattle, WA 98195, USA;(3) Biostatistics and Epidemiology, School of Public Health, Seoul National University, 28 Yunkeon-Dong, Chongro-Gu, Seoul, 100–799, Korea |